Label-free detection of platelet-derived growth factor-BB via liquid crystal/ aqueous interface functionalized using a double-stranded DNA probe

초록

A liquid crystal (LC)-filled transmission electron microscopy (TEM) grid cell coated with cationic surfactant octyltrimethylammonium bromide (OTAB) and adsorbed with a double-stranded deoxyribonucleic acid (dsDNA) probe at the LC/aqueous interface (TEMOTAB/DNA) was utilized for the highly specific detection of plateletderived growth factor (PDGF-BB). Upon adsorption of the OTAB-coated 4-cyano-4 '-pentylbiphenyl (5CB) on the TEM grid (TEMOTAB) and subsequent adsorption of the dsDNA probe, a homeotropic orientation was observed. Subsequently, the TEMOTAB/DNA biosensor was exposed to PDGF-BB, which induced a homeotropic-toplanar configurational change in 5CB, as observed using polarized optical microscopy with crossed polarizers. The optimized adsorption density of the dsDNA probe facilitated the detection of 2.63 pg mL-1 PDGF-BB in the detection range of 5-200 pg mL-1. Remarkably, this LC-based biosensor discriminated PDGF-BB from bovine serum albumin, immunoglobulin G, hemoglobin, carcinoembryonic antigen, epidermal growth factor, PDGF-AA, and PDGF-AB. The application potential of this sensor was further demonstrated by its effective performance in detecting PDGF-BB in both human serum and synthetic urine samples. Because of its high specificity, sensitivity, and label-free detection capabilities, this biosensor has potential applications in cancer detection.

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